In the past decades many controlled release technologies have appeared. However, for drug substances that can be absorbed through many segments of the gastrointestinal (GI) tract, there is still a need for developing compositions that enable sufficient absorption of the drug substance over broader range of segment of the gastrointestinal (GI) tract in order to enable a less frequent dosage of the drug and/or in order to avoid excretion of unabsorbed drug via the faeces.
Pharmacodynamics and pharmacokinetics challenges might enforce the need for special release patters (such as paracetamol in which the first pass metabolism makes it difficult to make a constant release unit work). Furthermore, the passage of material through the gastrointestinal tract is carefully controlled by several mechanisms. This “house-keeping” (intestinal peristalsis) might lead to anomalies in the effect of solid oral dosage forms which might be compensated by the formulation.
Furthermore, the active substance may exert its effect locally in the colon or other parts of the gastrointestinal system, such as for treatment of cancer, inflammation, gastrointestinal diseases and treatment with anthelmintic agents.